A 3D film about the world's largest cave in central Vietnam will be broadcast on Japanese TV channel NHK on June 25, local authorities announced Tuesday.
The documentary featuring the Son Doong Cave will reach 60 countries in the world, according to the Quang Binh Province Department of External Affairs.
A group of filmmakers from Japan's Kyodo News, accompanied by four British cave experts, started shooting the 3D film on May 7.
The team was accompanied by 20 locals, including Ho Khanh, who was considered the first person to actually find the cave in 1991 but then forgot the entrance.
They have overcome many difficulties and weather adversities including flash floods on the way to finish the first 3D film about the largest cave in the world, local authorities said.
On the evening of May 16, flash floods slammed to a stream near the En Cave in Phong Nha-Ke Bang National Park, where the filmmakers were camping.
Luckily, Khanh woke the team members up after hearing the sounds of fallen trees and swift waters.
They escaped death after running to a higher place, but all the food for the trip was swept away by floods.
It is not the first time the Son Doong Cave has been featured on television. In March 2010, a National Geographic team visited the cave on a 20-day expedition and later released a TV special about the world's biggest cave.
The Son Doong was discovered in 2009 by a caver team of the British Cave Research Association at the UNESCO-recognized world heritage site Phong Nha-Ke Bang National Park near the Laos-Vietnam border.
The cave measured at 200 meters high and 150 meters wide at its largest, nearly double the previous world's largest cave - the Deer Cave in Malaysia - which is 100 meters high and 90 meters wide.
Located above Son Doong, the expedition also found the En Cave measuring at 150 meters high and 130 meters wide.